Foam marquee letters are so popular right now. It is a great way to pack a big punch when decorating for a party. We are obsessed with making these DIY Foam Numbers for parties right now because they are so easy and inexpensive. When I first saw them, I knew I wanted to incorporate them into my husband’s surprise Golden 30th Birthday Party. After making one set, I knew I had to make a giant two for my daughter’s second birthday. These foam numbers are easy to make, require a little patience, but come together quick. Here is how to make a big foam marquee number.

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Supplies for How to Make a Big Foam Marquee Number

I had most of these things on hand so the total out of pocket cost was only $25 for all three numbers that I did. If you buy the pattern I did, it comes with different sizes. I made all my letters 5 feet and needed 7-8 foam core boards for each.

-Exacto knife (I like this one because it comes with a ton of extra blades, and this one comes with a mat)
-Foam core board ( the dollar store is the cheapest, but you can get it at Walmart or amazon
-1 roll white duct tape (amazon, target, walmart cheapest from target)
–This pattern for the number. This is the best price I have found and it comes with all the numbers
-Packing Tape (target, amazon, walmart I always buy the 6 pack because I use it a lot)
-Balloons (I like 5″ and the regular size blown up a tad smaller), this is a great starter pack.
-Pencil
-Spare box/ scrap box or a cutting board
-Level/ long ruler
–Balloon Pump– this pump is totally worth the investment ($23 at time of posting). We use it all the time.

How to Make a Big Foam Marquee Number

Check out the youtube video for a step by step guide to watch

Step One: Prepare the Number/ Pattern

-Print your pattern piece and tape it together. This is really easy because you just go in order. You will need a good amount of floor space. *You do not need to tape every bit of paper, just tape a small amount where the numbers actually connect to save on tape

-Cut out your number

Step Two: Tape Your Boards

-Using the packing tape on the backside of your foam core board, tape together two boards. You are taping together the two longest sides, not the short sides. You will want these very tight and close together. I tape the top and bottom horizontally to hold it into place before taping completely from top to bottom down the seam.

-After you have taped two board with clear tape, do the same to two more boards. 4 Boards are needed for the back of the number.

-Once you have your two sets of taped boards, flip them over to the side that isn’t taped. Using your white duct tape tape the vertical seam. Make sure it is as tight as you can together.

-Now that you have all 4 boards taped together (creating two large boards), flip the boards to the backside again and using the clear tape, tape the two sets of boards together to create one giant square. Your pattern piece should be able to fit on this so you will know if you are doing it right.

-Flip it back to the front and use the white duct tape to tightly secure the board.

Step Three: Trace Pattern and Cut

-Now that your board is prepped, place your giant pattern piece on the board, and tape a few of the edges to keep it from moving. You don’t want to tape too much because it can tear the board.

-Trace around the pattern piece with pencil or pen, it doesn’t really matter if it is super perfect or not because it isn’t going to really going to be noticeable once you cut it out. After you trace, remove the pattern piece from the foam board.

-Place your foam core board on a spare box, or cutting board. It does not have to be big, just remember to move the box underneath as you cut. Using your Exacto knife cut around the number following the line you just made. The best method I have found is to kind of saw back and forth. You do want this to be kind of clean, but if not you can just trim away the messy edges.

Step Four: Prepare Outer Edges

-Take your extra pieces of foam board and measure it into threes. It ends up being around 7.33″ or so. Cut the board into three strips. You want to be as clean as you can because the edges are going to show on the middle board. You can tape the edge (as shown in the first photo below). Depending on the size of number you are doing will depend on how many strips you need. I cut 6 originally and had to cut three more.

-Once you have your strips- lightly score them around 1.5-2 inches apart. Only work piece by piece with the scoring. Some pieces when going around a curve will need them closer together to lay flat around the curve. DO NOT cut through the whole board. If you do, its ok because you can tape it back together, but it is just easier to barely go through the foam.

-After scoring the board, gently bend every cut you have just made.

Step Five: Attaching the Outer Edges to the Number

-Using the clear packaging tape, you will attach the outer edges you just made, to the number. This task can be a little tricky, but become pretty easy once you get the hang of it.

– Lay the number wrong side down and with the rough edge of the side piece you have scored and cut, tape the edge to the side of the number. Do not put the board on top of number, it will not support itself as easy if you tape it to the side.

-When it comes time to connect the side pieces, make sure you line up the side piece to the front of the old side piece so if any sticks out or they were cut a tad off, the extra is toward the back because you can still maneuver the tape around the letter.

Step Six: Fill the Number

-Blow up tons of balloons and fill the number. The amount of balloons needed will vary on the size of number you make, but you want to use 5″ balloons and regular size that aren’t blow up as much.

-Tape the balloons carefully inside the number. You can also do this a day in advanced if needed and it will still look good. Fill the number with as many as you would like.

-Take a photo to see where there are missing spots, you can tell below mine needs some smaller balloons to fill in gaps

Step Seven: Display Your Number

That’s it, you are done with your DIY Big Foam Marquee Number. This project is so fun and simple and I cannot wait to see the numbers you have made with it.

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